Your time on the bike is precious, let make it even better. Ultegra ST-R8170 brake levers bring enhanced modulation and control to every ride by employing 's proven SERVO-WAVE technology. The Di2 platform untethers the shifters while delivering fast and reliable wireless shifting. The BR-R8170 hydraulic 2-piston disc brake caliper brings a new level of control to the road cycling world with improved modulation and a quicker initial braking point. Despite its smaller construction, the system is quieter than ever and easier to maintain. Includes L05A-RF pads. Includes fork adapter for 160mm rotors. The wireless connection provides a clean cockpit, enhancing the aerodynamic effect and easy maintenance. Wider pad clearance decreases brake noise. Maintenance-friendly bleeding process. Unparalelled ergonomic features, such as raised hood peaks on levers. Brake control is optimized with light and smooth lever action. Enhanced modulation thanks to an expanded braking control area. Compatible with wireless or wired connection. Item Specifications: Brake Lever Actuation: Hydraulic, Double or Triple: Double, Rotor Included: No, Brake Caliper Mount: Flat Mount, Brake Lever Use: Left, Rear Der/Shifter Compatibility: Road Di2, Drivetrain Speeds: 12, Front Der/Shifter Compatibility: Road Di2, Color: Black, Hydraulic Fluid Type: Mineral Oil, Pad Compound: Organic, Hydraulic Hose Length: 1000, Adjustable Reach: Yes, Defined Color: Black,